Process for producing variegated detergent bars

ABSTRACT

A PROCESS FOR THE MANUFACTURE OF VARIEGATED DETERGENT BARS OR CAKES INCLUDES PASSING DETERGENNT COMPOSITIONS OF SIMILAR SOLUBILITIES AND TEMPERATURES BUT OF DIFFERENT COLORS, IN SOLID PLASTIC STATES ALONG SUBSTANTIALLY PATHS, OUT OF PHYSICAL CONACT WITH EACH OTHER BUT PREFERABLY IN THERMAL CONTACT WITH EACH OTHER, EXTRUDING THE COMPOSITIONS, CUTTING THE EXTRUDATES TO LENGTHS, MIXING THE CUT EXTRUDATES TOGETHER AND, WHILE THEY ARE MIXED, MAINTAINING THEM AT AN ELEVATED TEMPERATURE AT WHICH THEY ARE PLASTIC AND MAY BE FUSED TOGETHER TIGHTLY, AND COMPACTING AND EXTRUDING THEM TO A VARIEGATED DETERGENT BAR FORM, WHICH MAY BE SUBSEQUENTLY PRESSED INTO VARIEGATED DETERGENT CAKES, SUCH AS SOAP CAKES. PREFERABLY, THE BASE DETERGENT COMPOSITION, E.G., A WHITE SOAP, IS PLODDED THROUGH A PLURALITY OF CYLINDRICAL TUBES WHILE A COLORED SOAP IS PLODDED BY A DIFFERENT PLODDER INTO THE SECTION OF A VARIEGATING HEAD AROUND SUCH TUBES, AFTER WHICH BOTH SOAPS ARE EXTRUDED AT SIMILAR VELOCITIES INTO A MIXING AND CONTACTING SECTION OF THE VARIEGATING HEAD, WHEREIN THEY ARE CUT TO LENGTHS AND A WHIRLING MOTION IS IMPARTED TO THE CUT PIECES BY A ROTATING CUTTER. ALSO DESCRIBED IS AN APPARATUS WHICH MAY BE USED IN PRACTICING THE PROCESS, INCLUDING A VARIEGATING HEAD CONTAINING THE MENTIONED TUBES, MEANS FOR FASTENING THE INLET PORTIONS THEREOF TO THE PLODDERS, TEMPERATURE AND CONTROL MEANS AND CUTTING AND WHIRLING MEANS FOR DISTRIBUTING ONE SOAP OR DETERGENT THROUGH THE OTHER BEFORE FINAL PLODDING.

y 9. 1974 A. DKARC ANGEU 3,823,215

PROCESS FOR PRODUCING VARIEGATED DETERGENT BARS Filed Jan. 12, 1972 sSheets-Sheet 1 PROCESS FUR PRODUCING VARIEGATED DETERGENT BARS FiledJan. 12. 1972 July 9, 1974 A. DARCANGELI 3 Sheets-Sheet 2 y 9, 1974 A.DARCANGELI 3,823,215

PROCESS FOR PRODUCING VARIEGATED DETERGENT BARS 3 Sheets-Sheet 5 FiledJan. 12. 1972 United States Patent 3,823,215 PROCESS FOR PRODUCINGVARIEGATED DETERGENT BARS Alessandro DArcangeli, 'Castelgandolfo, Italy,assignor to Colgate-Palmolive Company, New York, N.Y. Filed Jan. 12,1972, Ser. No. 217,110 Claims priority, application Italy, Jan. 23,1971, 47 ,924/ 7 1 Int. Cl. B29f 3/12 US. Cl. 264-75 6 Claims ABSTRACTOF THE DISCLOSURE A process for the manufacture of variegated detergentbars or cakes includes passing detergent compositions of similarsolubilities and temperatures but of different colors, in solid plasticstates along substantially parallel paths, out of physical contact witheach other but preferably in thermal contact with each other, extrudingthe compositions, cutting the extrudates to lengths, mixing the cutextrudates together and, while they are mixed, maintaining them at anelevated temperature at which they are plastic and may be fused togethertightly, and compacting and extruding them to a variegated detergent barform, which may be subsequently pressed into variegated detergent cakes,such as soap cakes. Preferably, the base detergent composition, e.g., awhite soap, is plodded through a plurality of cylindrical tubes while acolored soap is plodded by a different plodder into the section of avariegating head around such tubes, after which both soaps are extrudedat similar velocities into a mixing and contacting section of thevariegating head, wherein they are cut to lengths and a whirling motionis imparted to the cut pieces by a rotating cutter. Also described is anapparatus which may be used in practicing the process, including avariegating head containing the mentioned tubes, means for fastening theinlet portions thereof to the plodders, temperature control means andcutting and whirling means for distributing one soap or detergentthrough the other before fiinal plodding.

SUBJECT OF THE INVENTION This invention is of a process for makingvariegated detergent bars and cakes. More particularly, it is of amethod by which colored and uncolored soaps are blended together toproduce desirably marbled, mottled or striped soaps of attractive andsubstantailly reproducible appearances. In carrying out the process anapparatus may be employed in which a special head is provided forremovable aflixation to a pair of plodders, in which head the mixing ofthe soaps takes place and a variegated soap bar is produced.

BACKGROUND OF THE INVENTION Soap bars and cakes are presentlycommercially manufactured by substantially automatic methods whereinmilled chips, flakes or ribbons produced from mixtures of soaps andother components are plodded and extruded as bars, which aresubsequently cut to lengths and pressed into soap cakes or tablets.Often, to obtain best cohesiveness of the bar product the ploddingoperation takes place under vacuum so that air and other gases whichmight disrupt the continuity of the soap bar are removed. Soaps ofdifferent colors have been made by the addition of dyes and pigments tothe soap composion components in a mixing or amalgamating step whichantecedes the milling operation. In recent years a substantialproportion of toilet soaps and bath soaps manufactured have been coloredby such method.

Patented July 9, 1974 Variegated soaps and soaps containing coloredindicia of various types have been manufactured for many years.Beginning with framed soaps in which Prussian Blue or other dye orpigment had been stirred during the cooling process, such soaps haveenjoyed acceptances at various times. Nevertheless, for a number ofreasons they have not often been commercially marketed on a large scalein recent years. In some cases, the dye solutions added in the plodderare not sufiiciently sorbed by the soap and may rub off onto wrappingmaterials and the hands of a user, when the package is opened. Themarbling or other variegated patterns, obtained by addition of acoloring liquid in the plodder often differ greaterly between bars,depending on the particular movement in the plodder of the section ofsoap into which the dye has been incorporated. When mixtures of differtcolored soaps are charged to the plodder, usually as plodder bars,chips, filaments, ribbons or rods, the product obtained may be of asolid color, the resultant of the colors and proportions of the soapscharged. When attempts are made to blend the different colored soaps ata later point in a plodding operation, they may be unsatisfactorilyfused together, with the result that the user can note a roughness atthe interfaces between the different colored soaps.

Other reasons why variegated soaps have not become as popular as mightbe expected from their attractive appearances include processingdifliculties encountered. Thus, where white soap or a particular coloredsoap is the main material being made on a soap production line,interruption of such production to produce a variegated soap introducesa soap of a different color into the plodder. Before resumption ofnormal production, the plodder will have to be cleaned thoroughly toavoid having objectionable specks of the colored soap appear in the nextbars made. Also, to avoid marking of regular production soap with dye,the means for adding the dye or pigment will have to be thoroughlycleaned or completely removed from the plodder. When the colored portionof the variegated soap is made by milling the color into the soap chip,the cleaning procedure will also have to be undertaken on theamalgamator, mills rolls, bins, conveyors, elevators, chutes and otherequipment with which the colored product comes into contact.

What has been needed to popularize variegated soaps and correspondingdetergent composition cakes and bars is a simple, reproducible andtrouble free method of satisfactorily distributing coloring materialthrough a base soap or detergent which will result in a firm fusedproduct in which the coloring agent is held fast, at least until use,and which does not involve difficult or costly manufacturing operationsor apparatus modifications. Desirably, such method should be capable ofmodification to produce different types of variegations of the cleaningproducts. The described desirable properties are characteristic of thepresent process.

DESCRIPTION OF THE INVENTION In accordance with the present invention aprocess for the manufacture of a variegated detergent bar comprisesproducing a base detergent composition of one or more colors, producinga second detergent composition of one or more colors, at least one ofwhich contrasts with or is distinguishable from at least one of thecolor(s) of the first composition, and is of a solubility about that ofthe first composition, adjusting the temperature(s) of the first andsecond compositions so that they are about the same and are sufiicientlyelevated so that both compositions are plastic solids, passing bothcompositions at such an elevated temperature along substantiallyparallel paths with the path(s) of one composition being substantiallywithin the path(s) of the other composition but with the compositionsbeing out of contact with each other, forcing the 3 compositions throughseparate openings, producing interspersed extrusions of differentcolors, cutting off the extruded materials in short lengths, mixingtogether such short lengths of extrudates and, while maintaining themixed materials at an elevated temperature at which they are plastic andmay be fused together tightly, compacting them and forcing the compactedmass through an opening to produce a variegated detergent bar.

With respect to the apparatus which may be employed for carrying out theprocess, there is provided a variegating head adapted to be fastened toa plurality of means for feeding plastic solid detergent compositions,at least one of which is colored diiferently from another, saidvariegating head including a plurality of passageways for one of thedetergent compositions to be passed through but out of contact withanother of said compositions in a surrounding zone, with a plurality ofexit openings from the passageways and surrounding zone, through whichfilaments or rods of the diiferent detergent compositions can pass,means for cutting the rods or filaments into short lengths afterextrusion through said openings, means for imparting to the rods orfilaments a transverse or whirling motion, a mixing and compacting zonein which the rods and or filaments are further mixed, compacted andfused together tightly, and means for extrusion of the plastic detergentcomposition from the mixing and compacting zone, to form a variegateddetergent billet or bar.

Various objects, details, constructions, operations, uses and advantagesof the present invention, in its various aspects, will be apparent fromthe following description taken in conjunction with the accompanyingdrawing of apparatuses which may be employed to eifect the inventedprocess and the various products made, in which drawing:

THE DRAWING FIG. 1 is a partially schematic, partially sectional view ofa plurality of soap plodders of a soap production line, the last ofwhich plodders is equipped with a variegating head for the production ofvariegated plodder bars;

FIG. 2 is a central vertical sectional view of the variegating head ofFIG. 1, affixed to and in operative relationship with two of the soapplodders of FIG. 1;

FIG. 3 is a front perspective view of a portion of the variegating headof FIGS. 1 and 2;

FIG. 4 is a disassembled view of the variegating head portion of FIG. 3,with the cutter thereof removed;

FIG. 5 is a top view of a variegated detergent tablet pressed from a barmade according to the present invention;

FIG. 6 is a transverse vertical sectional view of the tablet of FIG. 5;

FIG. 7 is a longitudinal vertical sectional view of said tablet;

FIG. 8 is a top plan view of a striped detergent tablet made with theillustrated apparatus but without imparting a whirling motion to themixed colored rods or filaments in the variegating head;

FIG. 9 is a transverse vertical sectional view of the tablet of FIG. 8;and

FIG. 10 is a longitudinal vertical sectional View of the tablet of FIGS.8 and 9.

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 are illustrated plodders11, 13, and 15, which, in combination with variegating head 17, make upan apparatus for producing a variegated detergent bar 19, seen emergingfrom variegating head 17, from which it is moving toward the viewer. Inmixing and feeding tank 21 there is a solution of a dye or a dispersionof a water dispersible pigment 23 in an aqueous medium. It is maintaineduniform by stirrer 25 and is fed, continuously or intermittently, asdesired, to hopper 27 through control valve 29. Other means, not shownare provided for delivery of detergent chips, rods, powders or filamentsto hopper 27 and such soap or other detergent is then fed through aplodder 11 with the aqueous coloring material 23. In the illustrationgiven only a single barrel 31 is shown in the plodder with a single worm33 but plural barrels may be used, with plural worms, preferably withvacuum, jacketing of the plodder barrel(s), speed control of the worm(s)and remote control of the feeding of the coloring solution ordispersion. As illustrated, after the detergent is discharged throughperforated pressure plate 34, which may be equipped with a screen (notshown) to remove any foreign matter and better mix the soap or detergentconstituents together, the filaments or rods which exit from the plodderare cut by a revolving knife 35 and fall into hopper 37 of plodder 13'.The colored detergent, in rod or filament form, is carried by worm 39upwardly through water jacketed plodder barrel 41 in which it is kept ata desired temperature for proper plasticity, which temperature ismaintained due to a combination of the working of the detergent andcovering of the plodder barrel with a jacket in which there iscirculated water at a desired temperature.

From the second plodder, the colored detergent is forced upwardly intovariegating head 17, illustrated in more detail in FIG. 2. Uncoloreddetergent rods or filaments are fed into the variegating head 17 fromthe main soap line plodder 15, after having been worked in plodderbarrel 43. Plodder 15 is a two-worm vacuum plodder with the vacuum beingapplied in the chamber between the exit from the upper worm and theentrance to the lower worm. Plodder 15 is charged with detergentcomposition or soap chips through hopper 45. In place of white soap,other colored soap may be employed or a partly colored soap or detergentmay be used, providing that it will contrast with the other soap fed tothe variegating head, so that a variegated, mottled or marbledappearance mav be obtained in the finished product.

As is shown in FIG. 2, the colored soap 47 passes through jacketedintroductory connecting elbow 49, which is welded to a water jacketedcylinder 51. Elbow 49 is held by bolted flanges 53 and 55 or othersuitable means to plodder 13, and body portion 52 of variegating head 17is held to main line plodder 15 by pins and grooves, such as illustratedat 57 and 59, respectively. The white soap or other contrasting soapfrom the main line plodder 15 may be forced through a screen 61 and apressure plate 63 into plodder cone section 65 and thence intovariegating head 17. It then pursues a plurality of paths, indicated byarrows 67, through tubes, preferably cylinders 69, which are usuallymade of comparatively thin heat conductive metal so as to facilitate theequalizing of temperatures of the white and colored soaps in thevariegating head. The section of the head in which the parallel tubularpassageways 69 are located, including the surrounding volume about thepassageways, represented by numeral 71, is referred to as the parallelpaths zone, designated by numeral 73. It will be noted that although themain line white soap or detergent composition pursues a plurality ofparallel paths through tubular passageways, the colored soap fromplodder 13 moves transversely across the passageways but with partsthereof pursuing generally parallel paths and ultimately, before leavingsuch section, is moving parallel to the white soap. See arrows 74 whichrepresent flows of such soap. Tubes 69 are welded at both ends toframework or body 75 of the variegating head and have exit openings 77at the ends thereof which regulate the sizes of filaments or rods beingextruded from the parallel paths zone of the variegating head to acutting and mixing zone thereof 79. Similarly, the zone about theparallel tubes is blanked off at the portions 81 nearer to the main linesoap plodder but is open at orifices or exit openings 83 to producefilaments or rods of the colored detergent, which are sent through plate85, together with the extrusions from the parallel tubes, past cuttingknife 87 into cutting and mixing zone 79.

During the passing of the base detergent composition and the seconddetergent composition through the parallel paths zone the basecomposition is moving substantially within the paths of the secondcomposition, although out of physical contact with it. Alternatively, itmight be considered that the reverse situation is also true. Therefore,upon exiting from such zone the filaments, rods or particles of the twodifferently colored detergents are interspersed as they are forcedthrough the openings in plate 85 and into the cutting and mixing portionof the variegating head. Because such head is filled with detergentcomposition being extruded through nozzle 89 therein, a fairly regularstriped pattern would be produced if the rods or filaments beingextruded through plate 85 were uncut or not given transverse, radial orwhirling movements. To obtain a good degree of mottling or marblizing, arotating cutter 87 is employed. This is moved by shaft 93 which isconnected to the rotating worm of plodder 15. The knife may have fromone to 12 blades (in the illustration it has three blades). The surfaceswhich contact the extruded material are thick, generally being from 0.5to 2 cm. thick so that they will not just slide past the extruded rodsbut will push them or whirl them radially transversely through themoving mass of soap or detergent composition, thereby causing them to bespread out transversely and promoting the creation of the desiredmottled or marblized appearance of the detergent in the cutting andmixing zone of the variegating head. In preferred embodiments of theinvention a second impeller, propeller or other means for distributingthe differently colored soaps in the mixing zones will also be present.As shown, impeller 95, attached by shaft 97 to shaft 93, also rotatesand further aids in producing the desired marblized soap. Instead ofbeing held as illustrated, this second whirling device may be mounted torotate freely as the soap is forced past it, whereby transverse motionmay be given to the soap. Alternatively, partially radially inclinedpassageways in a stationary whirling device may have a similar desiredeffect. In either case, the distance between such means and the cuttingand whirling means previously mentioned will normally be from to 25 cm.

The rest of the cutting and mixing section of the variegating head maybe like a conventional jacketed plotter nozzle but is preferably of asomewhat different design. Thus, rather than having a tapered nosesection, like most conventional plodders, it will preferably have arather short nose and the taper will be more extreme. This design helpsto prevent streaking of the product during extrusion through nozzle 89.Nozzle 89 may be equipped with a nozzle plate, which can be heated,electrified, cooled or otherwise treated to promote best extrusion ofthe desired detergent bar. Also, outside the nozzle of the variegatinghead and attached to that head will preferably be located skinningknives 99 which remove surfaces from the plodder and expose bettervariegated interior detergent portions which, when subsequently pressed,make a more attractive marblize'd bar product. After cutting the plodderbar to length, it is pressed in a conventional soap press, notillustrated. The cutting and pressing may be so effected as to create abar having a longitudinal grain or one extending transversely throughthe thickness or width of the bar. Generally, however, it is preferredto have the grain longitudinal, since products so made are less apt toexhibit bad wet cracking during use.

FIGS. 3 and 4 illustrate the parallel paths zone or feeding portion ofthe variegating head with the inlet elbow from the colored soap plodderattached. The head has been rotated about 90 from the position of FIG.2. The various parts designated have the same meanings as previouslydescribed in conjunction with FIG. 2. The inlet and outlet lines to theWater jacket are indicated by numerals 101 and 103, respectively.Cutting blades 105, 107 and 109 are shown with greater clarity, as isthe hub 111 to which they are joined, forming cutter 91. As illustrated,the cutting and mixing section of the variegating head is joined to theparallel paths zone portion at flange 85, by conventional means, and isseparable from it.

In FIGS. 5-7 are shown various views of a marblized soap bar made by themethod of the present invention. In this case, however, the secondimpeller or mixing device in the cutting and mixing head of thevariegating means is omitted, since suflicient transverse or whirlingmotion of the colored soap particles is obtained with the first mixingdevice. As illustrated, the colored soap is satisfactorily dispersedthroughout the soap bar, on the face thereof, at 115 and throughout thebar, as at 117 and 119. The white soap base or matrix 121 surrounds thecolored soap and, as it wears down during use, exposes new surfaces ofthe colored detergent, so that the marblized appearance is substantiallyconstant during use. In FIGS. 8-10, corresponding views are given of abar made from substantially the same charges of white and colored soapsbut the cutting knife and mixer utilized in the cutting and mixing headto make the products of FIGS. 5-7 were removed before processing. Thus,the product resulting is striped, with the colored soap extendingsubstantially longitudinally through the bar. In FIGS. 8-10, numeral 123represents the colored striping detergent and numeral 125 is the basesoap.

The detergent composition employed is preferably a white or a lightcolored soap but may be any other suitable detergent, either anionic,cationic, nonionic or amphoteric or blend thereof, providing that it isnormally solid at room temperature, and is capable of being plasticizedduring manufacture so that a cohesive bar product may be obtained. Ofcourse, the colored or contrasting detergent or soap should possesssimilar properties and be sufficiently compatible with the base so asnot to result in degradation of either portion of the final bar due toobjectionable oxidation or other reactions. Although it is preferred toutilize a white base and a contrasting marblizing or variegating charge,mixtures of differently colored soaps or detergents may be used for eachand more than two different colored materials may be employed. In fact,the base may be of several colors, as may be the dispersed detergentcomposition.

Although the synthetic organic detergents and soaps are very well known,and are set forth in detail in the text, Synthetic detergents, Vol. II,by Schwartz, Perry and Berch, published in 1958 by IntersciencePublishers, Inc., the most preferred of these are the alkali metal saltsof straight chain higher fatty alcohol sulfuric acids; the alkali metalsalts, particularly the sodium salts, of higher linear alkyl benzenesulfonic acids; the sodium, potassium and ammonium salts of higher fattyacid monoglyceride sulfuric acids, e.g., those of 14 to 18 carbon atomsin the fatty acid groups; the solid Pluronics, condensation polymers ofethylene oxide with the condensate of propylene glycol and propyleneoxide; and the alkali metal sulfates of ethoxylated higher fattyalcohols. The soaps employed are those which are standard in commercialproduction today, blends of alkali metal soaps, preferably sodium soaps,of tallow and coconut oily fatty acids, or equivalent materials.Normally these will comprise from 50 to of tallow and from 10 to 50% ofcoconut oil fatty acid soaps. Preferred are those of 10 to 40% coconutoil soap and 60 to 90% tallow soap.

To make desired products which will be capable of being satisfactorilyused as toilet soaps or other washing aids, the physical characteristicsof both the uncolored and colored soaps should be essentially the same.Thus, they should be plastic within the same temperature ranges, usuallysomewhat elevated, and should have essentially the same watersolubilities, etc., so that they may hold together tightly and notpreferentially dissolve in use, leaving ridges and inequalities in theproduct. Accordingly, it will be usual for most of the base anddispersed material to be the same, with only slight differences thereindue to coloring materials, possibly due to perfumes, plasticizers, orminor proportions of adjuvants. Essentially, the compositions of thecontinuous and dispersed phases will be from 90 to the same. Of course,in addition to color unchanged and at other times'will be adapted foruse with the other parts of the present invention. For example,laboratory, small ,scale and large scale production plodders may beemployed. These may have speedcontrols, torque regulators, heating orcooling jackets, thermal controls,

automatic high pressure or high temperature alarms, etc, such as areknown and presently utilized. They'may be permanent installations or maybeportable, especially in -the case of the smaller plodders adapted tofeed colored soap to the variegating head. A number of such plodders isillustrated in US. Pats. 2,296,842; 2,495,005; 2,640,033; 2,649,417;3,268,970; 3,294,692; and 3,485,905. Some of the mentioned patentsrelate to the production of-variegated or mixed-color soaps but theapparatuses and methods used are different from those of the presentinvention.

In addition to the plodders employed, other 'conventiony al soap lineequipment will be used, including amalgamators, mills, elevators, otherfeeding devices and various measuring devices and automatic controls tohelp ordintae and synchronize the operations of the different machines.Such apparatuses, although important for the obtaining of the desiredchip, ribbon, rod, powder or other material to feed to the plodder, arewell known and do not relate closely to the present invention.Therefore, they are not described in detail here. I I

At the heart of the present process is the variegating head, equipped,in accordance with this invention, with structural elements for carryingout the process by which the desirably marblized or variegated detergentbar is produced. Thus, the head has a plurality of passageways,preferably tubular, and most preferably cylindrical, which are ofinternal diameters of from 0.4 or 0.5 to 2 centimeters and will usuallybe from 10 to 50 centimeters long. These tubes will form a number ofparallel passageways, generally from 3 to 100 and P eferably from 5 to50 through the parallel passageway zone of the variegating head. Thepassageways may be terminated by orifices thatare smaller than the tubesand such exit openings may be from 0.5 to millimeters, with one or moreopenings per tube. Similarly, the exist openings from the zone about thetubes may be in the same size range and of approximately the samenumber, although this is variable, depending on the degree of marblizingdesired. The effective area of the total number of orifices for the tubesection will be from 50 to 95%, preferably from 80 to 90% of the totalorifice area, including the exit orifices from the surrounding zone. Ofcourse, if so desired, the variegating head may be arranged so that thecolored soap is directed through the tubes and the base about it. Thetubes, while preferably straight and parallel to one another, may pursuedifferent paths so long as the essential path of the soaps passingthrough them is one which, at least toward the end of the journey,parallels the paths surrounding material being extruded.

For best operation of the variegating head to produce a most desirabledesign, it is normally preferred to have from 50 to 95% of one soap ordetergent composition and the balance of another. However, pluralcomponents may be employed with adjustments of such proportionscorrespondingly made. With soaps, the sodium soaps of higher fatty acidare preferred and these are desirably plastic when they contain from 5to 25% moisture, on a total basis. Nevertheless, soaps of moistures upto about 30%, e.g., floating soaps, may also be used. The soaps willusually be from 80 to 90% of sodium soaps of such higher fatty acids. Tomake such materials properly plas tic, the temperatures of the water oroil jackets employed about the plodders and the variegating head willusually be in the range of from 30 to 60 C. This range will be from 30to 50 C. for the plodding operations and from 40 to 60 C. for themixing, compacting and extrusion operations effected in the variegatinghead. Generally it will be desirable to utilize water jackets overplodder parts and at the parallel paths zone portion of the variegatinghead, with an oil jacket being used over the cutting and mixing sectionof such head. In either case, the temperature of the soap, for bestplodding and fusion will be from about 35 C. to 55 C., most preferablyfrom 38 C. to 45 C.

At the above conditions, with the described plodding and variegatingequipment, it will usually be a simple matter to product a variegated,marbled or mottled soap product of desired appearance and the soap made,if at the right plasticity and temperature will bond well, so thatboundary lines between parts thereof are not objectionable in use.However, when the hard milled soap bars are of moisture content lessthan 10% and when floating soaps are less than 20% moisture, bondingsmay be weakened unless there is a plasticizer present. In suchcases, upto about 10% of a plasticizer, such as water, glycerol, polyoxyethyleneglycol, sorbitol, other dior polyhydric alcohol of 2 to 10 carbon atomsand 2 to 6 hydroxyls, petrolatum, paraffin, stearic acid, other higherfatty acid of 10 to 18 carbon atoms, or a hydrotropic compound, such assodium xylene sulfonate, potassium cumene sulfonate, sodium benzenesulfonate or other lower alkyl-substituted benzene sulfonate may beadded to the detergent composition to improve the bonding strengththereof. In some preferred formulas water, glycerine, potassium soap andsodium toluene sulfonate, will be used together or in varioussubcombinations.

With soaps of usual plasticity for the manufacture of milled toiletbars, pressures reached in the plodders and in the extrusion heads maybe from 50 to 500 lbs/sq. in. although it will usually be preferred tooperate in the lower part of this range. Vacuum in the plodder may beanysubatmospheric pressure but will preferably be from 1- mm. to 300 mm.of Hg absolute, with the lower portions of this range being preferred todeaerate the soaps. Such vacuum will be employed, preferably, in all ofthe plodders being used. Motor speeds, worm pitches, diameters and rootdiameters may vary but usually will not depart much from those which areconventional in the usual soapmaking operations. Thus, worm speeds of 2to 50 rpm, preferably 5 to 35 rpm, are generally employed. The worm maybe of a diameter from two inches to 16 inches or even more, in somecases, but preferably will be between four and ten inches in diameter.The length of the worm and the barrel will usually be from three feet toten feet. Throughputs of soap may be from as little as one pound perminute to fifty or one hundred pounds per minute, depending on equipmentsizes.

Although the illustrated emboidments of apparatuses for practicing theinvention are considered to be most preferred, variations therein can bemade, some of which have already been mentioned. Instead of feeding thecolored soap to the variegating head from underneath, this may beeffected from the top or side and sometimes, different and attractivepatterns result from such variation. Instead of utilizing single barrelplodders for the auxiliary equipment, double barrel plodders may beemployed. In replacement of the second impeller or propeller in thevariegating head fixed vanes may be used for giving additionaltransverse movements to the differently colored detergent compositions.Materials of construction may be varied, depending on the composition ofthe detergent being processed. In most cases, stainless steel,polytetrafluoroethylene, nylon or other inert materials will bepreferred although often a good grade of steel may be employed,providing that the equipment is kept well cleaned and free from rust. Animportant structural feature of the present invention is to providemeans of joinder of the various pieces of equipment so that they may bereadily removed and the soap line may be quickly returned to productionof ordinary soap. Thus, the auxiliary plodders may be mounted onrollers, which may be locked when they are being used to feed the mainplodder. Quick disconnect fittings may be used between the variousplodders. The variegating head is preferably very easily removable sothat it may be inspected and conditions therein altered to change thevariegating pattern, when desired. Other modifications which aredesirable to utilize in certain situations will be apparent to those ofskill in the art.

In operation, the various plodders are connected together, asillustrated in FIG. 1, with the variegating head in position, as shownin FIGS. 1 and 2. Sufficient dye or pigment dispersion is fed to producea colored soap and this is passed through an auxiliary plodder to thevariegating head. Speeds of the worms in the auxiliary and principalplodders are regulated so that both colored and un-colored soaps are fedin correct porportion desired, for example, about colored soap and 90%uncolored. Temperatures in the various heating jackets, preferablyheating all the equipment, are regulated and heating fluids are flowedthrough them at sufficient rates to maintain the soaps at the desiredtemperature throughout. Thus, with the correct ratios of the soaps beingmainained by the feed mechanisms and the desired speeds of rotation ofthe worms, the colored and uncolored soaps enter the parallel pathportion of the variegating head. The openings in the plate and in thescreen adjacent to the end of the parallel paths portion are so chosenas to allow the proper feeding of the colored and uncolored soapsthrough them at the same linear speed. If it should be apparent that therates of feeds are disproportionate and result in the moving of one soappast the other, thereby causing streaking and preventing goodcompacting, modifications of the screen sizes or the feed rates may bemade. The soaps are then cut by the revolving knifepusher and are givena transverse or radial motion outward from the hub of the knife. Thisaction produces a desired marblizing effect. If the colored soap bodiesin the uncolored soap are too concentrated and a more diifusdistribution is desired, the number of knives may be increased or theirwidth decreased. On the contrary, if the pattern is not distinct enough,fewer knife blades of greater thickness may be desired. Usually thelength of the short rod or filament cut will be approximately the sameas the thickness of the knife blade. Different patterns of soap colorsalso result from raising or lowering soap temperatures. The degree ofdiffusion of color may also be controlled by utilizing a waterorsoapsoluble dye or a dispersible but insoluble pigment as coloringagents. The former gives a greater diffusion and less contrast, whereasthe latter tends to maintain a separate contrasing color more readily.To vary the pattern of the plodder bar mechanically is a simple matterand is soon learned by the worker utilizing the equipment. By varyingfeed rates, plate and screen openings, knife design, presence or absenceof an auxiliary distributor, proportions of colored and uncolored soaps,etc., a wide variety of variegated or marbling patterns may be obtained.Sometimes a different variegating head will be used, wherein thecompacting and extruding portions of the noses may be more or lesstapered, which also will modify the apparance of the final product. Oncethe pattern is chosen, by means of the present invention it is possibleto continue to reproduce similar patterns, although no two will beidentical.

Although in preferred embodiments of the invention the plodder bars orbillets made will be skinned after plodding to reveal most attractivesurfaces, this is not always necessary and sometimes may not bedesirable. However, if surface shaving is effected the shavings may bere- 10 turned to the first plodder in which soap is being colored, thusavoiding any waste.

The advantages of the present invention are many. It is simple tooperate and results in variegated soaps of reproducible designs. Becausethe soaps are given the same speed when being brought through thevariegating head into the cutting and mixing portions thereof (alsoreferred to as the mixing and compacting section), flow is more uniformand the soaps are fused together better. Yet, especially if theauxiliary plodding equipment is portable, the line may quickly bereturned to ordinary use. It is easy to adjust the design produced. Forexample, by changing of the knife-pusher or removal of it, differentmarbilized or granite effects may be obtained and by removing it astriped soap product may be produced. By using a floating soap chargeand not using vacuum (sometimes, air under pressure may be blown intothe plodders), a variegated floating soap may be made. Cleanouts areeasily performed and it is usually unnecessary to give the main ploddermore than an ordinary cleanout. All of these simplified operations helphave downtime on the soap line and contribute to its greatly increasedefficiency of operation.

The following examples illustrate the various embodiments of theinvention. Of course, the invention is not limited thereto. Unlessotherwise indicated, all temperatures are in C. and all parts are byweight.

EXAMPLE 1 A marbled soap of the type illustrated in FIGS. 5-7 is made byutilizing the equipment of FIGS. 1-4. The soap base comprises 95.7%sodium soap of a fat charge of 62% beef tallow and 38% coconut oil; 4%distilled palm oil fatty acids; and 0.3% of antioxidants, sequestrants(EDTA) and stabilizers. The soap, initially of a moisture content ofabout 33% (kettle soap), is dried to a moisture content of about 10.6%.It is then ready to be used as a soap base for a marblized product.

95.8 parts of the described soap base, 0.2 parts titanium dioxideAnatase, 1 part perfume, 2 parts water and 1 part glycerine are mixedtogether to produce a chip which, after moisture loss, has about 10%moisture content. Another soap, this one of a dark green color, is madeby milling 94.3 parts of the base chips, 0.3 parts titanium dioxide,Anatase, 1 part perfume, 1 part water and 1 part glycerine. To thismilled soap, in the first plodder, there is added an aqueous solution ofa water dispersible green pigment, 0.03 part Viscofil Green (Sandoz) in2 parts Water and 0.5 part glycerol. Then, the colored soap so producedis fed into the variegating head through the second auxiliary plodderand the base soap is fed through the main plodder, in proportion of 7:93. The production rate employed, while it may be varied, is about 30lbs./ min. and the feed rates are adjusted accordingly.

The various pieces of equipment are jacketed, with the worms of theplodders being water jacketed and with the water therein being held at atemperature of 25-35 C. The jacket on the variegating head is filledwith oil at 45-60" C.

The main plodder worm revolves at about 10 r.p.m., as does thethree-bladed cutting knife employed. The openings through which thesoaps pass into the variegating head are within the range of 2 to 5mrn., proportional in cross-sectional area to the 93:7 ratio of thesoaps employed. The cutting knife is 1 cm. thick. The second circulatingimpeller is not employed. During the plodding operations the soaptemperature is maintained at about 40 C. and in the variegating headthis is raised to about 45 C. Trimmings from the shaving device at thenozzle plate are recycled back to the coloring plodder.

As illustrated in the drawing, the base soap passes through the tubularpassageways, which number approximately 50, each of which is of adiameter of about 1 cm. From the pipes and surrounding area outlets of 2to 5 mm. diameter lead to the cutting and mixing zone of the 1 lvariegating head. These number about 130, with approximately half beingoutlets from the tubes.

Operating at a pressure of about 100 lbs./sq. in., a bar like that ofFIGS. 5-7 is produced and is pressed by conventional pressing equipment.

Using substantially the same formulation but With the addition of 6% ofsodium toluene sulfonate to the colored soap, slightly greaterpenetration of the colored soap into the White soap is noted. Similarly,when the knife thickness is halved, so that smaller rods or filamentsare cut off, the marblizing obtained is more diffuse. This is also notedwhen the jacket temperatures are raised so that plodding is at 45 C.,with the variegating zone temperature maintained at 50 C. In such cases,it is desirable to employ cooling means before pressing the soap.

When the mixer-cutter is removed from the variegating head, the productobtained is striped soap, resembling that of FIGS. 8-10. When thesecondary impeller is added to the primary mixer, a more extensivemarbling is noted.

EXAMPLE 2 A wide variety of soaps of mixed colors is produced byutilizing other coloring materials than the described Water dispersiblepigment. For example, pigments and dye such as Blue Iragon L/UD (Geigy);1390 Pink GT Vat Red No. 1 (D. F. Anstead, Ltd); C. I. Pigment Green 7(Geigy, Sandoz); C. I. Pigment Red 6 (Geigy) are employed. SoaporWater-soluble dyes are also used to obtain a more diffused variegatedproduct and in some cases, a mixture of the pigments and dyes areemployed. In these formulas, the soap composition is varied to 85%tallow soap and 15% coconut oil soap, with no addition of fatty acids.The moisture content of the soap is 14% and the proportions of coloredand uncolored or differently colored soaps are varied over the rangefrom 50:50 to 5:95, preferably 25:75 to 5:95. The products obtained areall variegated, marblized soaps of attractive appearances. In each case,by removal of the cutter-mixer, striped soaps are made.

It is noted that whether or not the colored shavings are returned andrecycled, the appearance of the soap is substantially the same.

EXAMPLE a The procedures of Examples 1 and 2 are repeated but with thebase soap also being colored and of a contrasting color with that of thecolored soap fed by the auxiliary plodders. Coloring of the base soap iseffected with water-soluble and soap-soluble dyes which are added to thekettle soap before removal of the moisture therefrom, so that the colorsare uniformly distributed, preferably making pastel shades. The productsmade are attractive marbilized soaps in which the contrasts are usuallysubdued than those of Examples 1 and 2, when the dyes or pigmentsemployed for both charged are of similar or compatible colors.

The products made are tested by practical washing tests and found to besatisfactorily bonded together. They do not wash away unevenly and arenot rough or pebbly after use. By incorporation of 3 to of plasticizingagents, such as Water, hydrotrope salt, oil or glycerol, or mixturethereof, the bond is further improved and the surface of the bar afterwashing is even smoother. Also, penetration of the colored soap into theother soap is improved.

EXAMPLE 4 The experiments of Examples l-3 are repeated with 30% of thesoap replaced by sodium lauryl sulfate or with 70% of the soap replacedby a mixture of magnesium stearate and linear higher alkyl benzenesulfonate, sodium salt. Such synthetic detergent-soap combination barsare also produced in marblized form and have the desirable cohesivenessand Washing properties previously mentioned.

The invention has been described with respect to various embodimentsthereof but it will be appreciated that it is not limited to these,since it will be obvious to one of skill in the art to substituteequivalents for various elements of the invented processes andapparatuses.

What is claimed is:

1. A process for the manufacture of a variegated detergent bar whichcomprises producing a base detergent composition of one or more colors,producing a second detergent composition of one or more colors, at leastone of which contrasts with or is distinguishable from at least one ofthe color(s) of the first composition and is of a solubility about thatof the first composition, adjusting the temperature(s) of the first andsecond compositions so that they are about the same and are sufiicientlyelevated so that both compositions are plastic solids, passing bothcompositions at such an elevated temperature along substantiallyparallel paths with the path (s) of one composition being substantiallywithin the path(s) of the other composition but with the compositionsbeing separated from each other so as to be out of physical contact butwith heat being able to pass from one to the other while they are out ofphysical contact with each other, forming the compositions intofilaments or rods and bringing them into physical moving contact Whilemaintaining their paths substantially parallel, cutting off thefilaments or rods in equal short lengths and simultaneously giving themtransverse motions and mixing them together and, while maintaining themixed material at an elevated temperature at whch it is plastic and maybe fused together tightly, compacting the particles thereof andextruding the compacted mass to produce a variegated detergent bar.

2. A process according to claim 1 wherein the first and secondcompositions are separately plodded, with temperature control, into azone in which they pursue substantially parallel paths, with the pathsof one composition being of circular cross-section and straight, thefilaments or rods produced, after and during cutting are movedtransversely while being mixed with other short lengths of suchfilaments and rods of different color and being fused together withthem, the compacted mass is extruded to produce a marblized detergentbar, and said bar is cut to length and is pressed into final detergentcake form.

3. A process according to claim 2 wherein the first detergentcomposition is a soap base of one color, the second detergentcomposition is a soap of another color, both compositions are extrudedas rods into a mixing and compacting zone and are cut and movedtransversely therein, the flow of materials through the parallel pathzone being controlled so that they move at about the same speed throughsuch zone and during extrusion, to diminish streaking, the skin of theextruded bar is removed and the bar is cut to a length greater than itsmaximum width and is pressed into final soap cake form.

4-. A process according to claim 3 wherein the soap base is of a lightercolor than the second soap, a softening or plasticizing compound ispresent in the soap base and/ or the second soap to aid in subsequentfusion of the soaps together and to prevent any rough or pebbly feelingat the interface of the soaps during use thereof, the temperatures atwhich the soaps are plodded, passed through substantially parallel pathsout of contact with each other, extruded as filaments or rods, cut,mixed, compacted and extruded in bar form are from 30 to 60 C., Walls oftubular passageways separate the detergent compositions before extrusionto filaments or rods and are heat conductive and aid in equalizing thetemperatures of the soaps in the parallel paths Zone, and the rods orfilaments extruded into the mixing and compacting zone have diametersfrom 0.5 to 5 millimeters.

5. A process according to claim 4 wherein the soap base comprises fromabout to of the final marblized soap cake, the second soap comprises thebalance thereof, the soaps each comprise from about 80 to 99% of sodiumsoaps of higher fatty acids, on an anhydrous basis, and from tomoisture, on a total product basis, at least one of the soaps isplasticized with a material from the group selected from the groupconsisting of dihydric or polyhydric alcohols of 2 to 10 carbon atomsand 2 to 6 hydroxyls, higher fatty acids of 10 to 18 carbon atoms,polyoxyethylene glycols and hydrotropic compounds and the cutting of therods and mixing of them by transverse movement thereof is elfected by arotating knife.

6. A process according to claim 5 wherein plodding operations areeffected at a temperature in the range of to C., mixing, compacting andextrusion operations are effected at a temperature in the range of 40 toC., and mixing effected in the mixing and compacting zone is at twosections thereof from 5 to 25 centimeters apart, both of which includerotating means for imparting transverse motions to the differentlycolored soaps.

References Cited UNITED STATES PATENTS Marshall 264-148 Matthaei 264-Hackmann 425-131 Duggins 264-75 Compa et a1. 264-75 Patterson 264-75Hoglin 425-131 Compa 252-109 15 JEFFERY R. THURLOW, Primary Examiner US.Cl. X.R.

